#include <stdio.h>
int main()
{
    printf("%d\n", sizeof(char));
    printf("%d\n", sizeof(short));
    printf("%d\n", sizeof(int));
    printf("%ld\n", sizeof(long));
    printf("%lld\n", sizeof(long long));

    signed char a = 100;   // 有符号的 signed 可以忽略
    unsigned char b = -100; // 无符号的
    printf("%d and %u\n", a, b);

    // 数据溢出
    char c = 128;
    printf("%d\n", c);

    return 0;
}
